1. Field of the Invention
The present invention relates to an image forming apparatus, for example, a copier or a printer, which has a function of forming an image on a recording material such as a sheet.
2. Description of the Related Art
As an image forming apparatus such as a copier or a laser printer, an image forming apparatus configured to use an intermediate transfer member has been known.
In such an image forming apparatus, first, a primary transfer step is carried out in which, with a toner image formed on a surface of a drum-like electrophotographic photosensitive member (hereinafter referred to as a photosensitive drum), a primary transfer member disposed opposite the photosensitive drum is supplied with a voltage by a high-voltage power supply to transfer the toner image to an intermediate transfer member. Then, the primary transfer step is repeatedly carried out for a plurality of toner images in respective colors to form a plurality of toner images in the respective colors on the surface of the intermediate transfer member. Subsequently, in a secondary transfer step, a secondary transfer member is supplied with a voltage by the high-voltage power supply to transfer all of the plurality of toner images in the respective colors formed on the intermediate transfer member to a surface of a recording material such as paper at a time. Then, fixing means fixes the toner images to the recording material to form a color image on the recording material.
Japanese Patent Application Laid-open No. 2001-175092 discloses a configuration in which a current is passed through the intermediate transfer member in a circumferential direction thereof via a transfer member in contact with an inner peripheral surface of the intermediate transfer member or a tensing member tensing the intermediate transfer member to carry out the primary transfer step by the current flowing through the intermediate transfer member in the circumferential direction thereof. However, Japanese Patent Application Laid-open No. 2001-175092 may fail to sufficiently supply the current needed for the primary transfer step, resulting in an inappropriate image.